<html><style>body{color:red;background:url('my file.png');border:1px solid red;}a+b,a+c,#my_style,#my-style{color:blue;}.a .b{color: green;}a #b,c#d,e.f{color:#ff0;}a:hover{content:'hello, world!; '}</style><body><h1>Hello, world!</h1></body></html>